Seal

ABSTRACT

A seal formed of molded resilient plastic material, including a housing through which a shackle is passed, said housing having internal integral shackle engaging fingers. The shackle is provided with annular shoulders for engagement by the fingers so that the shackle can be drawn through the housing in one direction, but is prevented from retrograde movement. The end portion of the shackle is provided with annular enlarged portions which may be drawn through the housing without excessive pulling force being required, yet provides a surface providing for gripping by the fingers. A portion of the shackle between two adjacent annular shoulders is provided with a weakened portion to insure that when sufficient tension is applied, the shackle will fracture at that position, with said position being predetermined for the application in which the seal is to be used, so that the fracture occurs within the housing.

United States Patent [191 Moberg I [451 Aug. 20, 1974 SEAL [75]Inventor: Sigurd M. Moberg, Orange, NJ.

[73] Assignee: E. J. Brooks Company, Newark,

[22] Filed: June 1, 1972 [21] Appl. No.: 258,608

[52] US. Cl. 292/322 [51] Int. Cl. G09f 3/00 [58] Field of Search292/307, 318, 320, 321,

292/322; 24/16 PB, 30.5 PB, 208.3

[56] References Cited UNITED STATES PATENTS 2,372,811 4/1945 Conaway etal. 292/322 X 3,368,247 2/1968 Orban 24/16 PB 3,402,435 9/1968 Merser292/322 X 3,467,427 9/1969 Moberg 292/322 3,597,803 8/1971 Van Neil t24/16 PB 3,600,027 8/1971 Noland 292/322 Primary Examiner-Richard E.Moore Attorney, Agent, or FirmRobert E. Ross [57] ABSTRACT A seal formedof molded resilient plastic material, including a housing through whicha shackle is passed, said housing having internal integral shackleengaging fingers. The shackle is provided with annular shoulders forengagement by the fingers so that the shackle can be drawn through thehousing in one direction, but is prevented from retrograde movement. Theend portion of the shackle is provided with annular enlarged portionswhich may be drawn through the housing without excessive pulling forcebeing required, yet provides a surface providing for gripping by thefingers. A portion of the shackle between two adjacent annular shouldersis provided with a weakened portion to insure that when sufficienttension is applied, the shackle will fracture at that position, withsaid position being predetermined for the application in which the sealis to be used, so that the fracture occurs within the housing.

2 Claims, 5 Drawing Figures SEAL BACKGROUND OF THE INVENTION US. Pat.No. 3,467,427 discloses a seal having a housing with a passagetherethrough for receiving a shackle. The shackle has a plurality ofrearwardly facing shoulders which cooperate with resilient fingerswithin the housing to allow the shackle to be drawn through the housingbut to prevent retrograde movement of the shackle.

SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWINGS In thedrawing:

FIG. 1 is a top plan view of a seal embodying the features of theinvention;

FIG. 2 is a view in side elevation of the seal of FIG.

FIG. 3 is a top plan view, partly in section, of the seal of FIGS. 1 and2 assembled with a closure mechanism;

FIG. 4 is a view in section taken on line 4-4 of FIG.

FIG. 5 is a view similar to FIG. 3 after the shackle of the seal hasbeen tightened and the end broken off.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENT Referring to the drawing,there is illustrated a seal 10, which is adapted for assembly with aclosure mechanism 12 to indicate whether said mechanism has been openedby unauthorized personnel. Although the presence of the seal will notprevent the opening of the mechanism and pilferage of the contents, itwill provide evidence of the removal of the contents, since the closuremember cannot be opened without rupturing the seal.

The seal is preferably formed of a single piece of molded plastic suchas polyethylene or polypropylene, and comprises a housing 14 and ashackle 16 for insertion into the housing to form a loop for extendingthrough suitable apertures 18 and 20 in the operating portions of theclosure member.

The housing 14 is formed of a relatively thick wall section 26 and athinner wall section 28 extending upwardly therefrom, terminating in arestricted neck 30. An aperture 32 extends through the housing toreceive the shackle, and to retain the shackle locked in the housing, aseries of resilient fingers 34 extend upwardly and inwardly from thethick wall section 18.

The shackle 16 is provided with a plurality of annular locking portionseach of which comprises a forward camming surface 36 leading to arearwardly facing shoulder 38. The remote end portion of the shackle isprovided with annular bulges 40 for a purpose to appear hereinafter.

To insure that the shackle will break at the desired point, an annulargoove 42 is provided in the shackle between a predetermined pair ofannular locking portions.

In the particular embodiment of the invention, the seal is designed foruse with a closure assembly of a par ticular size so that thecircumferential distance to be enclosed by the seal is known, and thegroove 42 is disposed at a position on the shackle which will be withinthe housing when the seal is tightened around the two portions 22 and 24of the closure assembly.

To assemble the seal, the shackle is inserted through the apertures 18and 20, inserted into the bottom of the housing, and pushed through thehousing far enough that the end portion can be grasped by the fingers atthe top of the housing. Thereafter the shackle is pulled through thehousing until it tightens around the portions 22 and 24, at which pointthe groove 42 is positioned inside the housing. As the shackle lockingelement passes through the housing, the fingers 26 flex outwardly oneach camming surface 28 and snap inwardly behind each shoulder 30 as itpasses. When the groove 42 is positioned inside the housing, furthertension applied to the shackle causes it to rupture at the groove 34,and the fingers 26 seat behind the shoulder 30 of the adjacent lockingportion, preventing retraction of the shackle. Thereafter no portion ofthe shackle protrudes from the housing, which might assist in unlockingthe seal without destruction or evidence of tampering.

The bulges 40 on the end of the shackle provide sufficient friction whengripped by the fingers to allow adequate tension to be applied to theshackle to accomplish both the tightening of the shackle and therupturing at the groove 42, yet do not provide appreciable resistance toinsertion through the housing.

In the illustrated embodiment a plurality of locking elements areillustrated, although in a particular application only the one adjacentthe groove 42 is required. However, in the manufacture of plasticmolding dies, it is relatively economical to have one set of dies with aplurality of locking elements and a die insert to form the groove 34,which insert may be positioned between any desired pair of lockingelements, as established by the length of the shackle loop required toencircle the object to which the seal is to be applied. However, in thecase of an application in which the seal is to be used in very highvolume, it may be economical to build a special set of dies, in whichcase only one locking element would be required.

Since certain obvious changes may be made in the illustrated devicewithout departing from the scope of the invention, it is intended thatall matter contained herein be interpreted in an illustrative and not alimiting sense.

I claim:

1. A seal, comprising a housing and a shackle attached at one end to thehousing, and having a series of locking elements disposed thereon withone portion disposed between a predetermined pair of adjacent lockingelements having a cross-sectional area less than that of any otherportion of the shackle, said housing having an aperture extendingtherethrough and resilient means in the aperture permitting movement ofthe locking elements therethrough in one direction but preventingretrograde movement, said one portion being so positioned on the shacklethat when the seal it tightspaced longitudinally rounded enlargedportions having an overall diameter less that that of the lockingelements which allow said remote end to be pushed through the housingwithout excessive resistance, but provide sufficient friction whengripped by the fingers to enable the locking portions to be pullsedthrough the housing.

1. A seal, comprising a housing and a shackle attached at one end to thehousing, and having a series of locking elements disposed thereon withone portion disposed between a predetermined pair of adjacent lockingelements having a crosssectional area less than that of any otherportion of the shackle, said housing having an aperture extendingtherethrough and resilient means in the aperture permitting movement ofthe locking elements therethrough in one direction but preventingretrograde movement, said one portion being so positioned on the shacklethat when the seal it tightened around the article with which it isintended for use, said one portion is disposed inside the housing, andadditional tension applied to the shackle will cause rupture of theshackle at said one portion, whereby no portion of the fractured end ofthe shackle protrudes from the housing.
 2. A seal as set forth in claim1 in which the remote end portion of the shackle is provided with aseries of spaced longitudinally rounded enlarged portions having anoverall diameter less that that of the locking elements which allow saidremote end to be pushed through the housing without excessiveresistance, but provide sufficient friction when gripped by the fingersto enable the locking portions to be pullsed through the housing.